I am creating a website using HTML (no visual editors at all - please do not suggest me one), and I want to add an accounts system. I have already made an example database, a signup/login form but I wonder about something. Is there a stable address that can be received and processed, and every device has one? I am asking this because I also want to make a connections table where all the devices' addresses will be located, along with the account they are linked to.
Is there a way to receive this address, and keep it even after the browser, device, and everything is closed?
If it is, please tell me. I prefer pure JavaScript, but, if there is only a way to do it in jQuery, then, I'll have to learn jQuery :(.
There is no unique stable identifier for each device or user (unless you generate one, and store it in e.g. local storage/cookies, and even then it could always be removed by the user and you'd regenerate one).
You seem to be looking for cookies, though, if you want to keep an user logged in on their device after having created an account.
Related
Is a very simple page, that have some buttons redirecting to external links. That external links have to change arbitrarely when certain people decides it.
I was wondering about making a login screen in other page and depending which user logs in, set the link writting it in a txt file that would be recovered by the main page. Don't need security so i just would make the user go to the other page and login and that would change the link in a txt file hosted in the same directory that the index.html is.
The problem is that i cannot make that idea (writing a .txt in the project folder) with JavaScript (or i think so), and i don't think that using a database worth it (neither want to because i read that would have to use node.js or something like that and i really don't know those tecnologies, only some python and sql server -that is in fact not supported by my hosting service-), cause are just 3 people associated to 1 link each. I can easily make that task with python but don't know how to call it from JS and neither if Ajax request would be useful for this case.
I hope someone can help me!
edit - the changes have to apply for the page itself not in the user session, so everyone who enters see the page with the changes
edit 2 - absolutely all the info (users and links) are always the same, doesnt change so i can put it in variables, are just 4 or 5 so i can easily use an array, the only thing that i would have to register is which one to pick (since it depends on who decides it).
IT seems you want to use some sort of client side storage across different html pages - for that, you can use cookies, localSotrage or sessionStorage.
I am having a really hard time figuring out how I am going to handle printing in my Nodejs application. I have a website where there is a bunch of purchase numbers. I want the users to print this numbers in a click of a button. These numbers are dynamically generated after querying the database.
I started using this npm library to print the purchase number. When I am developing in my local computer this library is working fine. I made it so that each time the user presses a button in the front end, I make a post request to my Nodejs Server which prints to the printer that I configured locally.
The problem is that I want to eventually deploy my website to Heroku. Website will be used by a group of people sharing the same network and printer. I do not know of a way to set heroku to communicate with the printer using this package.
I also thought that printing directly from the front end might be a better idea, but I have to open google on kiosk mode and then do the same for all the users that are going to use this website. Also, most of the users will be using a tablet device so configuring printer in those devices will be difficult as well.
I did not find anything online that I can use as a reference. Any advice or suggestion will be greatly appreciated.
As for nodeJs printing I have no experience. It seems that you can use certain packages to print a pdf as given in the example answer here: Node.js : How to add print job to printer.
As for generating from html to PDF, that should be easy to find, less easy to style correctly though.
I would recommend doing it from HTML (you could still do the PDF conversion for more stable printing results)
From HTML
As stated, the API is rather limited, you can use window.print to request a print action.
Note though that you have some options to make your life better when calling window.print().
You can create the page in a separate window to get rid of bloat, like navigation etc, or you could actually hide that with css.
You might already be aware of css being included for certain targets e.g. for your website you probably want to use the screen target, but you can create a separate stylesheet for printing.
More info at mozilla
https://developer.mozilla.org/en-US/docs/Web/Guide/Printing
I have created a webpage but my friends or collegues always copy the source code and copy all the data easily, so is there any way to hide page source option from browser ?
As a rule, if you are putting information on another user's computer (whether because you made a document or they viewed your webpage), you really can't control what they do with it.
This is an issue that larger companies deal with often. Have you heard of DRM? It's a mechanism that companies like to try to use to control how people can connect to their services, use their content and in general, try to exert control over their data while it's on your system.
Now, a web page is a relatively simple container for holding information. You expressed an urge to prevent your friends from copying the source code. You could try to encrypt it, but if it's using local data to decrypt itself, there still isn't going to be anything that stops them from just copying what's in the View Source window and running it again (even if they can't really read it).
I'd suggest that you don't worry about it. If what you have on your page is so important that others shouldn't be able to see it, don't put it on a webpage.
Finally, Google doesn't much care that you're able to view the source to their home page. Why not? Because the value of the search engine isn't in what the home page looks like, but in the data on the back-end that you don't have direct access to. The value is in the algorithms that execute on the server when you hit that Google Search button that queries that data and returns the information you're looking for. There's very little relative value in the generated HTML that you see in the page. Take a leaf from their book and don't stress that they copy your HTML.
No , there isnt any way to do it, however you can disable right clicking in browser via javascript, but still they can use shortkeys to open developer view (in chrome F12) and see the source. You cannot hide html or javascript from client, but maybe you can make it harder to read.
No. Your HTML output is in the user's realm. Even if there was a way to disable view source in one client, a user could use a different one
Always assume that your site's HTML is fully available to end users.
Yes and no. You can definitely make HTML and JS harder to intrepret by obfuscating your code - that is, taking your code and making it look confusing. Here is a tool that can do that: http://www.colddata.com/developers/online_tools/obfuscator.shtml
However, these things all use code, and code can be decrypted through any number of methods. If you post a song to the internet, even if they cannot find the mp3, they can simply record their speakers. If you upload an image and prevent users from downloading it, they can take a screenshot or use their camera. In order for HTML and Javascript to work, it has to be intrepreted by their computer, and even if you do find a way to disable "View Source" there are others ways, like a DOM inspector (F12 in IE/Chrome, Ctrl+Shift+K in Firefox).
As a workaround, use copyright, warn your users they will be punished if they copy your code, and put watermarks, labels and logos over any mp3s or images you don't want stolen. In the end, disabling right clicking (which is also possible, see How do I disable right click on my web page? ) or disabling selection (also possible) does nothing, because there is more than one way to get your code, like searching through temporary internet files.
However, you ask "what if I want a site where my users can log in and I need security? How can I make it so nobody can see my code then? Doesn't it have to be secure and not out in the open?"
And the answer is, yes, it needs to be secure. That's what server-side languages, like PHP, are for. PHP does all the work on the server itself so the user cannot see it. PHP is like a pre-rendered language - rather than doing it in real-time, PHP does all the work beforehand so the user's computer doesn't have to, making the code safe. The code is never put onto the user's computer, because the user's computer doesn't need it. The work is done by the website itself before the page is sent. SSL is often paired with PHP to make absolutely sure that websites have not been hacked.
But HTML and Javascript have to be done in real time on the user's computer, so you cannot disable View Source because it is useless. There are many, many ways that users could get around it, even if View Source is disabled, and even if right clicking is disabled.
If your code doesn't need to be secure, however, I'd recommend you consider keeping it open source. :)
The Context:
You have a web server which has to provide an exclusive content only if your client has your specific Chrome extension installed.
You have two possibilities to provide the Chrome extension package:
From the Chrome Web Store
From your own server
The problem:
There is a plethora of solutions allowing to know that a Chrome extension is installed:
Inserting an element when a web page is loaded by using Content Scripts.
Sending specific headers to the server by using Web Requests.
Etc.
But there seems to be no solution to check if the Chrome extension which is interacting with your web page is genuine.
Indeed, as the source code of the Chrome extension can be viewed and copied by anyone who want to, there seems to be no way to know if the current Chrome extension interacting with your web page is the one you have published or a cloned version (and maybe somewhat altered) by another person.
It seems that you are only able to know that some Chrome extension is interacting with your web page in an "expected way" but you cannot verify its authenticity.
The solution?
One solution may consist in using information contained in the Chrome extension package and which cannot be altered or copied by anyone else:
Sending the Chrome extension's ID to the server? But how?
The ID has to be sent by you and your JavaScript code and there seems to be no way to do it with an "internal" Chrome function.
So if someone else just send the same ID to your server (some kind of Chrome extension's ID spoofing) then your server will consider his Chrome extension as a genuine one!
Using the private key which served when you packaged the application? But how?
There seems to be no way to access or use in any way this key programmatically!
One other solution my consist in using NPAPI Plugins and embed authentication methods like GPG, etc. But this solution is not desirable mostly because of the big "Warning" section of its API's doc.
Is there any other solution?
Notes
This question attempts to raise a real security problem in the Chrome extension's API: How to check the authenticity of your Chrome extension when it comes to interact with your services.
If there are any missing possibilities, or any misunderstandings please feel free to ask me in comments.
I'm sorry to say but this problem as posed by you is in essence unsolvable because of one simple problem: You can't trust the client. And since the client can see the code then you can't solve the problem.
Any information coming from the client side can be replicated by other means. It is essentially the same problem as trying to prove that when a user logs into their account it is actually the user not somebody else who found out or was given their username and password.
The internet security models are built around 2 parties trying to communicate without a third party being able to imitate one, modify or listen the conversation. Without hiding the source code of the extension the client becomes indistinguishable from the third party (A file among copies - no way to determine which is which).
If the source code is hidden it becomes a whole other story. Now the user or malicious party doesn't have access to the secrets the real client knows and all the regular security models apply. However it is doubtful that Chrome will allow hidden source code in extensions, because it would produce other security issues.
Some source code can be hidden using NPAPI Plugins as you stated, but it comes with a price as you already know.
Coming back to the current state of things:
Now it becomes a question of what is meant by interaction.
If interaction means that while the user is on the page you want to know if it is your extension or some other then the closest you can get is to list your page in the extensions manifest under app section as documented here
This will allow you to ask on the page if the app is installed by using
chrome.app.isInstalled
This will return boolean showing wether your app is installed or not. The command is documented here
However this does not really solve the problem, since the extension may be installed, but not enabled and there is another extension mocking the communication with your site.
Furthermore the validation is on the client side so any function that uses that validation can be overwritten to ignore the result of this variable.
If however the interaction means making XMLHttpRequests then you are out of luck. Can't be done using current methods because of the visibility of source code as discussed above.
However if it is limiting your sites usability to authorized entities I suggest using regular means of authentication: having the user log in will allow you to create a session. This session will be propagated to all requests made by the extension so you are down to regular client log in trust issues like account sharing etc. These can of course be managed by making the user log in say via their Google account, which most are reluctant to share and further mitigated by blocking accounts that seem to be misused.
I would suggest to do something similar to what Git utilises(have a look at http://git-scm.com/book/en/Git-Internals-Git-Objects to understand how git implements it), i.e.
Creating SHA1 values of the content of every file in your
chrome-extension and then re-create another SHA1 value of the
concatenated SHA1 values obtained earlier.
In this way, you can share the SHA1 value with your server and authenticate your extension, as the SHA1 value will change just in case any person, changes any of your file.
Explaining it in more detail with some pseudo code:
function get_authentication_key(){
var files = get_all_files_in_extension,
concatenated_sha_values = '',
authentication_key;
for(file in files){
concatenated_sha_values += Digest::SHA1.hexdigest(get_file_content(file));
}
$.ajax({
url: 'http://example.com/getauthkey',
type: 'post'
async: false,
success:function(data){
authentication_key = data;
}
})
//You may return either SHA value of concatenated values or return the concatenated SHA values
return authentication_key;
}
// Server side code
get('/getauthkey') do
// One can apply several type of encryption algos on the string passed, to make it unbreakable
authentication_key = Digest::<encryption>.hexdigest($_GET['string']);
return authentication_key;
end
This method allows you to check if any kind of file has been changed maybe an image file or a video file or any other file. Would be glad to know if this thing can be broken as well.
I was just looking at this stackoverflow question: Display web browser settings
And that helps.
But, I'm curious if I can detect certain IE specific settings. I'm thinking some of the stuff in the Advanced Tab (e.g. Is 'Enable Integrated Windows Authentication' on)?
Or that our site was added as a Trusted Site? And within the Trusted Site settings, "Atomatic logon with current user name and password" is set?
I don't want to change them (I get that would be a huge issue that could be exploited). I just want to be able to present to the User:
"Hey, you need these couple of settings checked or unchecked for the site to work properly. Do this: a, b, c ... or Contact your Administrator".
Is this possible?
I don't think you can query these settings from within a web site. Being able to do so might introduce security holes.
I'm sure some settings can be determined by using circumstantial evidence (like if a JavaScript doesn't execute, scripting is probably disabled). But I don't think there is a proper API to poll every setting; I guess the best you can do is serve the user some advice on what to look for. (like, "The xyz symbol in the bottom right bar should show a green checkmark like so.... the abc checkbox in the options dialog should be unchecked... etc")
You can't check the settings directly, but you could test the functionality instead. If you attempt to authenticate with the server and find out you don't have their credentials passed in properly, you know it's not configured right. At this point you could show them your information about how to connect to the site. This would be a better solution anyways, as you're better off testing for features rather than specific settings.
To distill your question down, it looks like you're trying to find out whether IE is configured to automatically send NTLM credentials to your server.
Unfortunately, there's no way to cleanly feature-detect this. My initial thought was to put a JavaScript file in a protected directory that simply set a global variable, and link to that script in the <head>. (<script src="protected-dir/test.js"></script> – protected-dir would be configured only for integrated auth with anonymous auth off.) If the script loads, the variable is set; and if it fails, the variable obviously isn't. Another script on the page could check the variable and show a message if it's not set.
This works flawlessly when everything is configured correctly on a client, but when auto login is off, this causes an ugly 401 dialog to pop up, which is clearly no good. Additionally, a XHR request isn't the answer since the spec specifically says the browser should ask for credentials if it gets a 401.
Sadly, I don't think there's a way to automatically determine if auto login is enabled without causing the 401 dialog to pop up.